1/*
2 * Copyright (c) 2014 Christoph Hellwig.
3 */
4#include <linux/kmod.h>
5#include <linux/file.h>
6#include <linux/jhash.h>
7#include <linux/sched.h>
8#include <linux/sunrpc/addr.h>
9
10#include "pnfs.h"
11#include "netns.h"
12#include "trace.h"
13
14#define NFSDDBG_FACILITY                NFSDDBG_PNFS
15
16struct nfs4_layout {
17	struct list_head		lo_perstate;
18	struct nfs4_layout_stateid	*lo_state;
19	struct nfsd4_layout_seg		lo_seg;
20};
21
22static struct kmem_cache *nfs4_layout_cache;
23static struct kmem_cache *nfs4_layout_stateid_cache;
24
25static struct nfsd4_callback_ops nfsd4_cb_layout_ops;
26static const struct lock_manager_operations nfsd4_layouts_lm_ops;
27
28const struct nfsd4_layout_ops *nfsd4_layout_ops[LAYOUT_TYPE_MAX] =  {
29	[LAYOUT_BLOCK_VOLUME]	= &bl_layout_ops,
30};
31
32/* pNFS device ID to export fsid mapping */
33#define DEVID_HASH_BITS	8
34#define DEVID_HASH_SIZE	(1 << DEVID_HASH_BITS)
35#define DEVID_HASH_MASK	(DEVID_HASH_SIZE - 1)
36static u64 nfsd_devid_seq = 1;
37static struct list_head nfsd_devid_hash[DEVID_HASH_SIZE];
38static DEFINE_SPINLOCK(nfsd_devid_lock);
39
40static inline u32 devid_hashfn(u64 idx)
41{
42	return jhash_2words(idx, idx >> 32, 0) & DEVID_HASH_MASK;
43}
44
45static void
46nfsd4_alloc_devid_map(const struct svc_fh *fhp)
47{
48	const struct knfsd_fh *fh = &fhp->fh_handle;
49	size_t fsid_len = key_len(fh->fh_fsid_type);
50	struct nfsd4_deviceid_map *map, *old;
51	int i;
52
53	map = kzalloc(sizeof(*map) + fsid_len, GFP_KERNEL);
54	if (!map)
55		return;
56
57	map->fsid_type = fh->fh_fsid_type;
58	memcpy(&map->fsid, fh->fh_fsid, fsid_len);
59
60	spin_lock(&nfsd_devid_lock);
61	if (fhp->fh_export->ex_devid_map)
62		goto out_unlock;
63
64	for (i = 0; i < DEVID_HASH_SIZE; i++) {
65		list_for_each_entry(old, &nfsd_devid_hash[i], hash) {
66			if (old->fsid_type != fh->fh_fsid_type)
67				continue;
68			if (memcmp(old->fsid, fh->fh_fsid,
69					key_len(old->fsid_type)))
70				continue;
71
72			fhp->fh_export->ex_devid_map = old;
73			goto out_unlock;
74		}
75	}
76
77	map->idx = nfsd_devid_seq++;
78	list_add_tail_rcu(&map->hash, &nfsd_devid_hash[devid_hashfn(map->idx)]);
79	fhp->fh_export->ex_devid_map = map;
80	map = NULL;
81
82out_unlock:
83	spin_unlock(&nfsd_devid_lock);
84	kfree(map);
85}
86
87struct nfsd4_deviceid_map *
88nfsd4_find_devid_map(int idx)
89{
90	struct nfsd4_deviceid_map *map, *ret = NULL;
91
92	rcu_read_lock();
93	list_for_each_entry_rcu(map, &nfsd_devid_hash[devid_hashfn(idx)], hash)
94		if (map->idx == idx)
95			ret = map;
96	rcu_read_unlock();
97
98	return ret;
99}
100
101int
102nfsd4_set_deviceid(struct nfsd4_deviceid *id, const struct svc_fh *fhp,
103		u32 device_generation)
104{
105	if (!fhp->fh_export->ex_devid_map) {
106		nfsd4_alloc_devid_map(fhp);
107		if (!fhp->fh_export->ex_devid_map)
108			return -ENOMEM;
109	}
110
111	id->fsid_idx = fhp->fh_export->ex_devid_map->idx;
112	id->generation = device_generation;
113	id->pad = 0;
114	return 0;
115}
116
117void nfsd4_setup_layout_type(struct svc_export *exp)
118{
119	struct super_block *sb = exp->ex_path.mnt->mnt_sb;
120
121	if (!(exp->ex_flags & NFSEXP_PNFS))
122		return;
123
124	if (sb->s_export_op->get_uuid &&
125	    sb->s_export_op->map_blocks &&
126	    sb->s_export_op->commit_blocks)
127		exp->ex_layout_type = LAYOUT_BLOCK_VOLUME;
128}
129
130static void
131nfsd4_free_layout_stateid(struct nfs4_stid *stid)
132{
133	struct nfs4_layout_stateid *ls = layoutstateid(stid);
134	struct nfs4_client *clp = ls->ls_stid.sc_client;
135	struct nfs4_file *fp = ls->ls_stid.sc_file;
136
137	trace_layoutstate_free(&ls->ls_stid.sc_stateid);
138
139	spin_lock(&clp->cl_lock);
140	list_del_init(&ls->ls_perclnt);
141	spin_unlock(&clp->cl_lock);
142
143	spin_lock(&fp->fi_lock);
144	list_del_init(&ls->ls_perfile);
145	spin_unlock(&fp->fi_lock);
146
147	vfs_setlease(ls->ls_file, F_UNLCK, NULL, (void **)&ls);
148	fput(ls->ls_file);
149
150	if (ls->ls_recalled)
151		atomic_dec(&ls->ls_stid.sc_file->fi_lo_recalls);
152
153	kmem_cache_free(nfs4_layout_stateid_cache, ls);
154}
155
156static int
157nfsd4_layout_setlease(struct nfs4_layout_stateid *ls)
158{
159	struct file_lock *fl;
160	int status;
161
162	fl = locks_alloc_lock();
163	if (!fl)
164		return -ENOMEM;
165	locks_init_lock(fl);
166	fl->fl_lmops = &nfsd4_layouts_lm_ops;
167	fl->fl_flags = FL_LAYOUT;
168	fl->fl_type = F_RDLCK;
169	fl->fl_end = OFFSET_MAX;
170	fl->fl_owner = ls;
171	fl->fl_pid = current->tgid;
172	fl->fl_file = ls->ls_file;
173
174	status = vfs_setlease(fl->fl_file, fl->fl_type, &fl, NULL);
175	if (status) {
176		locks_free_lock(fl);
177		return status;
178	}
179	BUG_ON(fl != NULL);
180	return 0;
181}
182
183static struct nfs4_layout_stateid *
184nfsd4_alloc_layout_stateid(struct nfsd4_compound_state *cstate,
185		struct nfs4_stid *parent, u32 layout_type)
186{
187	struct nfs4_client *clp = cstate->clp;
188	struct nfs4_file *fp = parent->sc_file;
189	struct nfs4_layout_stateid *ls;
190	struct nfs4_stid *stp;
191
192	stp = nfs4_alloc_stid(cstate->clp, nfs4_layout_stateid_cache);
193	if (!stp)
194		return NULL;
195	stp->sc_free = nfsd4_free_layout_stateid;
196	get_nfs4_file(fp);
197	stp->sc_file = fp;
198
199	ls = layoutstateid(stp);
200	INIT_LIST_HEAD(&ls->ls_perclnt);
201	INIT_LIST_HEAD(&ls->ls_perfile);
202	spin_lock_init(&ls->ls_lock);
203	INIT_LIST_HEAD(&ls->ls_layouts);
204	ls->ls_layout_type = layout_type;
205	nfsd4_init_cb(&ls->ls_recall, clp, &nfsd4_cb_layout_ops,
206			NFSPROC4_CLNT_CB_LAYOUT);
207
208	if (parent->sc_type == NFS4_DELEG_STID)
209		ls->ls_file = get_file(fp->fi_deleg_file);
210	else
211		ls->ls_file = find_any_file(fp);
212	BUG_ON(!ls->ls_file);
213
214	if (nfsd4_layout_setlease(ls)) {
215		put_nfs4_file(fp);
216		kmem_cache_free(nfs4_layout_stateid_cache, ls);
217		return NULL;
218	}
219
220	spin_lock(&clp->cl_lock);
221	stp->sc_type = NFS4_LAYOUT_STID;
222	list_add(&ls->ls_perclnt, &clp->cl_lo_states);
223	spin_unlock(&clp->cl_lock);
224
225	spin_lock(&fp->fi_lock);
226	list_add(&ls->ls_perfile, &fp->fi_lo_states);
227	spin_unlock(&fp->fi_lock);
228
229	trace_layoutstate_alloc(&ls->ls_stid.sc_stateid);
230	return ls;
231}
232
233__be32
234nfsd4_preprocess_layout_stateid(struct svc_rqst *rqstp,
235		struct nfsd4_compound_state *cstate, stateid_t *stateid,
236		bool create, u32 layout_type, struct nfs4_layout_stateid **lsp)
237{
238	struct nfs4_layout_stateid *ls;
239	struct nfs4_stid *stid;
240	unsigned char typemask = NFS4_LAYOUT_STID;
241	__be32 status;
242
243	if (create)
244		typemask |= (NFS4_OPEN_STID | NFS4_LOCK_STID | NFS4_DELEG_STID);
245
246	status = nfsd4_lookup_stateid(cstate, stateid, typemask, &stid,
247			net_generic(SVC_NET(rqstp), nfsd_net_id));
248	if (status)
249		goto out;
250
251	if (!fh_match(&cstate->current_fh.fh_handle,
252		      &stid->sc_file->fi_fhandle)) {
253		status = nfserr_bad_stateid;
254		goto out_put_stid;
255	}
256
257	if (stid->sc_type != NFS4_LAYOUT_STID) {
258		ls = nfsd4_alloc_layout_stateid(cstate, stid, layout_type);
259		nfs4_put_stid(stid);
260
261		status = nfserr_jukebox;
262		if (!ls)
263			goto out;
264	} else {
265		ls = container_of(stid, struct nfs4_layout_stateid, ls_stid);
266
267		status = nfserr_bad_stateid;
268		if (stateid->si_generation > stid->sc_stateid.si_generation)
269			goto out_put_stid;
270		if (layout_type != ls->ls_layout_type)
271			goto out_put_stid;
272	}
273
274	*lsp = ls;
275	return 0;
276
277out_put_stid:
278	nfs4_put_stid(stid);
279out:
280	return status;
281}
282
283static void
284nfsd4_recall_file_layout(struct nfs4_layout_stateid *ls)
285{
286	spin_lock(&ls->ls_lock);
287	if (ls->ls_recalled)
288		goto out_unlock;
289
290	ls->ls_recalled = true;
291	atomic_inc(&ls->ls_stid.sc_file->fi_lo_recalls);
292	if (list_empty(&ls->ls_layouts))
293		goto out_unlock;
294
295	trace_layout_recall(&ls->ls_stid.sc_stateid);
296
297	atomic_inc(&ls->ls_stid.sc_count);
298	update_stateid(&ls->ls_stid.sc_stateid);
299	memcpy(&ls->ls_recall_sid, &ls->ls_stid.sc_stateid, sizeof(stateid_t));
300	nfsd4_run_cb(&ls->ls_recall);
301
302out_unlock:
303	spin_unlock(&ls->ls_lock);
304}
305
306static inline u64
307layout_end(struct nfsd4_layout_seg *seg)
308{
309	u64 end = seg->offset + seg->length;
310	return end >= seg->offset ? end : NFS4_MAX_UINT64;
311}
312
313static void
314layout_update_len(struct nfsd4_layout_seg *lo, u64 end)
315{
316	if (end == NFS4_MAX_UINT64)
317		lo->length = NFS4_MAX_UINT64;
318	else
319		lo->length = end - lo->offset;
320}
321
322static bool
323layouts_overlapping(struct nfs4_layout *lo, struct nfsd4_layout_seg *s)
324{
325	if (s->iomode != IOMODE_ANY && s->iomode != lo->lo_seg.iomode)
326		return false;
327	if (layout_end(&lo->lo_seg) <= s->offset)
328		return false;
329	if (layout_end(s) <= lo->lo_seg.offset)
330		return false;
331	return true;
332}
333
334static bool
335layouts_try_merge(struct nfsd4_layout_seg *lo, struct nfsd4_layout_seg *new)
336{
337	if (lo->iomode != new->iomode)
338		return false;
339	if (layout_end(new) < lo->offset)
340		return false;
341	if (layout_end(lo) < new->offset)
342		return false;
343
344	lo->offset = min(lo->offset, new->offset);
345	layout_update_len(lo, max(layout_end(lo), layout_end(new)));
346	return true;
347}
348
349static __be32
350nfsd4_recall_conflict(struct nfs4_layout_stateid *ls)
351{
352	struct nfs4_file *fp = ls->ls_stid.sc_file;
353	struct nfs4_layout_stateid *l, *n;
354	__be32 nfserr = nfs_ok;
355
356	assert_spin_locked(&fp->fi_lock);
357
358	list_for_each_entry_safe(l, n, &fp->fi_lo_states, ls_perfile) {
359		if (l != ls) {
360			nfsd4_recall_file_layout(l);
361			nfserr = nfserr_recallconflict;
362		}
363	}
364
365	return nfserr;
366}
367
368__be32
369nfsd4_insert_layout(struct nfsd4_layoutget *lgp, struct nfs4_layout_stateid *ls)
370{
371	struct nfsd4_layout_seg *seg = &lgp->lg_seg;
372	struct nfs4_file *fp = ls->ls_stid.sc_file;
373	struct nfs4_layout *lp, *new = NULL;
374	__be32 nfserr;
375
376	spin_lock(&fp->fi_lock);
377	nfserr = nfsd4_recall_conflict(ls);
378	if (nfserr)
379		goto out;
380	spin_lock(&ls->ls_lock);
381	list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
382		if (layouts_try_merge(&lp->lo_seg, seg))
383			goto done;
384	}
385	spin_unlock(&ls->ls_lock);
386	spin_unlock(&fp->fi_lock);
387
388	new = kmem_cache_alloc(nfs4_layout_cache, GFP_KERNEL);
389	if (!new)
390		return nfserr_jukebox;
391	memcpy(&new->lo_seg, seg, sizeof(lp->lo_seg));
392	new->lo_state = ls;
393
394	spin_lock(&fp->fi_lock);
395	nfserr = nfsd4_recall_conflict(ls);
396	if (nfserr)
397		goto out;
398	spin_lock(&ls->ls_lock);
399	list_for_each_entry(lp, &ls->ls_layouts, lo_perstate) {
400		if (layouts_try_merge(&lp->lo_seg, seg))
401			goto done;
402	}
403
404	atomic_inc(&ls->ls_stid.sc_count);
405	list_add_tail(&new->lo_perstate, &ls->ls_layouts);
406	new = NULL;
407done:
408	update_stateid(&ls->ls_stid.sc_stateid);
409	memcpy(&lgp->lg_sid, &ls->ls_stid.sc_stateid, sizeof(stateid_t));
410	spin_unlock(&ls->ls_lock);
411out:
412	spin_unlock(&fp->fi_lock);
413	if (new)
414		kmem_cache_free(nfs4_layout_cache, new);
415	return nfserr;
416}
417
418static void
419nfsd4_free_layouts(struct list_head *reaplist)
420{
421	while (!list_empty(reaplist)) {
422		struct nfs4_layout *lp = list_first_entry(reaplist,
423				struct nfs4_layout, lo_perstate);
424
425		list_del(&lp->lo_perstate);
426		nfs4_put_stid(&lp->lo_state->ls_stid);
427		kmem_cache_free(nfs4_layout_cache, lp);
428	}
429}
430
431static void
432nfsd4_return_file_layout(struct nfs4_layout *lp, struct nfsd4_layout_seg *seg,
433		struct list_head *reaplist)
434{
435	struct nfsd4_layout_seg *lo = &lp->lo_seg;
436	u64 end = layout_end(lo);
437
438	if (seg->offset <= lo->offset) {
439		if (layout_end(seg) >= end) {
440			list_move_tail(&lp->lo_perstate, reaplist);
441			return;
442		}
443		lo->offset = layout_end(seg);
444	} else {
445		/* retain the whole layout segment on a split. */
446		if (layout_end(seg) < end) {
447			dprintk("%s: split not supported\n", __func__);
448			return;
449		}
450		end = seg->offset;
451	}
452
453	layout_update_len(lo, end);
454}
455
456__be32
457nfsd4_return_file_layouts(struct svc_rqst *rqstp,
458		struct nfsd4_compound_state *cstate,
459		struct nfsd4_layoutreturn *lrp)
460{
461	struct nfs4_layout_stateid *ls;
462	struct nfs4_layout *lp, *n;
463	LIST_HEAD(reaplist);
464	__be32 nfserr;
465	int found = 0;
466
467	nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lrp->lr_sid,
468						false, lrp->lr_layout_type,
469						&ls);
470	if (nfserr) {
471		trace_layout_return_lookup_fail(&lrp->lr_sid);
472		return nfserr;
473	}
474
475	spin_lock(&ls->ls_lock);
476	list_for_each_entry_safe(lp, n, &ls->ls_layouts, lo_perstate) {
477		if (layouts_overlapping(lp, &lrp->lr_seg)) {
478			nfsd4_return_file_layout(lp, &lrp->lr_seg, &reaplist);
479			found++;
480		}
481	}
482	if (!list_empty(&ls->ls_layouts)) {
483		if (found) {
484			update_stateid(&ls->ls_stid.sc_stateid);
485			memcpy(&lrp->lr_sid, &ls->ls_stid.sc_stateid,
486				sizeof(stateid_t));
487		}
488		lrp->lrs_present = 1;
489	} else {
490		trace_layoutstate_unhash(&ls->ls_stid.sc_stateid);
491		nfs4_unhash_stid(&ls->ls_stid);
492		lrp->lrs_present = 0;
493	}
494	spin_unlock(&ls->ls_lock);
495
496	nfs4_put_stid(&ls->ls_stid);
497	nfsd4_free_layouts(&reaplist);
498	return nfs_ok;
499}
500
501__be32
502nfsd4_return_client_layouts(struct svc_rqst *rqstp,
503		struct nfsd4_compound_state *cstate,
504		struct nfsd4_layoutreturn *lrp)
505{
506	struct nfs4_layout_stateid *ls, *n;
507	struct nfs4_client *clp = cstate->clp;
508	struct nfs4_layout *lp, *t;
509	LIST_HEAD(reaplist);
510
511	lrp->lrs_present = 0;
512
513	spin_lock(&clp->cl_lock);
514	list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt) {
515		if (ls->ls_layout_type != lrp->lr_layout_type)
516			continue;
517
518		if (lrp->lr_return_type == RETURN_FSID &&
519		    !fh_fsid_match(&ls->ls_stid.sc_file->fi_fhandle,
520				   &cstate->current_fh.fh_handle))
521			continue;
522
523		spin_lock(&ls->ls_lock);
524		list_for_each_entry_safe(lp, t, &ls->ls_layouts, lo_perstate) {
525			if (lrp->lr_seg.iomode == IOMODE_ANY ||
526			    lrp->lr_seg.iomode == lp->lo_seg.iomode)
527				list_move_tail(&lp->lo_perstate, &reaplist);
528		}
529		spin_unlock(&ls->ls_lock);
530	}
531	spin_unlock(&clp->cl_lock);
532
533	nfsd4_free_layouts(&reaplist);
534	return 0;
535}
536
537static void
538nfsd4_return_all_layouts(struct nfs4_layout_stateid *ls,
539		struct list_head *reaplist)
540{
541	spin_lock(&ls->ls_lock);
542	list_splice_init(&ls->ls_layouts, reaplist);
543	spin_unlock(&ls->ls_lock);
544}
545
546void
547nfsd4_return_all_client_layouts(struct nfs4_client *clp)
548{
549	struct nfs4_layout_stateid *ls, *n;
550	LIST_HEAD(reaplist);
551
552	spin_lock(&clp->cl_lock);
553	list_for_each_entry_safe(ls, n, &clp->cl_lo_states, ls_perclnt)
554		nfsd4_return_all_layouts(ls, &reaplist);
555	spin_unlock(&clp->cl_lock);
556
557	nfsd4_free_layouts(&reaplist);
558}
559
560void
561nfsd4_return_all_file_layouts(struct nfs4_client *clp, struct nfs4_file *fp)
562{
563	struct nfs4_layout_stateid *ls, *n;
564	LIST_HEAD(reaplist);
565
566	spin_lock(&fp->fi_lock);
567	list_for_each_entry_safe(ls, n, &fp->fi_lo_states, ls_perfile) {
568		if (ls->ls_stid.sc_client == clp)
569			nfsd4_return_all_layouts(ls, &reaplist);
570	}
571	spin_unlock(&fp->fi_lock);
572
573	nfsd4_free_layouts(&reaplist);
574}
575
576static void
577nfsd4_cb_layout_fail(struct nfs4_layout_stateid *ls)
578{
579	struct nfs4_client *clp = ls->ls_stid.sc_client;
580	char addr_str[INET6_ADDRSTRLEN];
581	static char *envp[] = {
582		"HOME=/",
583		"TERM=linux",
584		"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
585		NULL
586	};
587	char *argv[8];
588	int error;
589
590	rpc_ntop((struct sockaddr *)&clp->cl_addr, addr_str, sizeof(addr_str));
591
592	trace_layout_recall_fail(&ls->ls_stid.sc_stateid);
593
594	printk(KERN_WARNING
595		"nfsd: client %s failed to respond to layout recall. "
596		"  Fencing..\n", addr_str);
597
598	argv[0] = "/sbin/nfsd-recall-failed";
599	argv[1] = addr_str;
600	argv[2] = ls->ls_file->f_path.mnt->mnt_sb->s_id;
601	argv[3] = NULL;
602
603	error = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
604	if (error) {
605		printk(KERN_ERR "nfsd: fence failed for client %s: %d!\n",
606			addr_str, error);
607	}
608}
609
610static int
611nfsd4_cb_layout_done(struct nfsd4_callback *cb, struct rpc_task *task)
612{
613	struct nfs4_layout_stateid *ls =
614		container_of(cb, struct nfs4_layout_stateid, ls_recall);
615	LIST_HEAD(reaplist);
616
617	switch (task->tk_status) {
618	case 0:
619		return 1;
620	case -NFS4ERR_NOMATCHING_LAYOUT:
621		trace_layout_recall_done(&ls->ls_stid.sc_stateid);
622		task->tk_status = 0;
623		return 1;
624	case -NFS4ERR_DELAY:
625		/* Poll the client until it's done with the layout */
626		/* FIXME: cap number of retries.
627		 * The pnfs standard states that we need to only expire
628		 * the client after at-least "lease time" .eg lease-time * 2
629		 * when failing to communicate a recall
630		 */
631		rpc_delay(task, HZ/100); /* 10 mili-seconds */
632		return 0;
633	default:
634		/*
635		 * Unknown error or non-responding client, we'll need to fence.
636		 */
637		nfsd4_cb_layout_fail(ls);
638		return -1;
639	}
640}
641
642static void
643nfsd4_cb_layout_release(struct nfsd4_callback *cb)
644{
645	struct nfs4_layout_stateid *ls =
646		container_of(cb, struct nfs4_layout_stateid, ls_recall);
647	LIST_HEAD(reaplist);
648
649	trace_layout_recall_release(&ls->ls_stid.sc_stateid);
650
651	nfsd4_return_all_layouts(ls, &reaplist);
652	nfsd4_free_layouts(&reaplist);
653	nfs4_put_stid(&ls->ls_stid);
654}
655
656static struct nfsd4_callback_ops nfsd4_cb_layout_ops = {
657	.done		= nfsd4_cb_layout_done,
658	.release	= nfsd4_cb_layout_release,
659};
660
661static bool
662nfsd4_layout_lm_break(struct file_lock *fl)
663{
664	/*
665	 * We don't want the locks code to timeout the lease for us;
666	 * we'll remove it ourself if a layout isn't returned
667	 * in time:
668	 */
669	fl->fl_break_time = 0;
670	nfsd4_recall_file_layout(fl->fl_owner);
671	return false;
672}
673
674static int
675nfsd4_layout_lm_change(struct file_lock *onlist, int arg,
676		struct list_head *dispose)
677{
678	BUG_ON(!(arg & F_UNLCK));
679	return lease_modify(onlist, arg, dispose);
680}
681
682static const struct lock_manager_operations nfsd4_layouts_lm_ops = {
683	.lm_break	= nfsd4_layout_lm_break,
684	.lm_change	= nfsd4_layout_lm_change,
685};
686
687int
688nfsd4_init_pnfs(void)
689{
690	int i;
691
692	for (i = 0; i < DEVID_HASH_SIZE; i++)
693		INIT_LIST_HEAD(&nfsd_devid_hash[i]);
694
695	nfs4_layout_cache = kmem_cache_create("nfs4_layout",
696			sizeof(struct nfs4_layout), 0, 0, NULL);
697	if (!nfs4_layout_cache)
698		return -ENOMEM;
699
700	nfs4_layout_stateid_cache = kmem_cache_create("nfs4_layout_stateid",
701			sizeof(struct nfs4_layout_stateid), 0, 0, NULL);
702	if (!nfs4_layout_stateid_cache) {
703		kmem_cache_destroy(nfs4_layout_cache);
704		return -ENOMEM;
705	}
706	return 0;
707}
708
709void
710nfsd4_exit_pnfs(void)
711{
712	int i;
713
714	kmem_cache_destroy(nfs4_layout_cache);
715	kmem_cache_destroy(nfs4_layout_stateid_cache);
716
717	for (i = 0; i < DEVID_HASH_SIZE; i++) {
718		struct nfsd4_deviceid_map *map, *n;
719
720		list_for_each_entry_safe(map, n, &nfsd_devid_hash[i], hash)
721			kfree(map);
722	}
723}
724